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Finding the Fourth Proportional to 856.76, 1,285.09 and 271.78

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Solution

The fourth proportional to 856.76, 1,285.09 and 271.78 is: 407.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.76 : 1,285.09 = 271.78 : x
  2. Step 2: Convert to fraction form
    856.76/1,285.09 = 271.78/x
  3. Step 3: Cross multiply
    856.76x = 1,285.09 × 271.78
  4. Step 4: Simplify right side
    856.76x = 349,257.87
  5. Step 5: Solve for x
    x = 349,257.87/856.76
  6. Step 6: Final answer
    x = 407.65

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.